PWM
Time-proportioning pulse-width modulated output with minimum on- and off-times and a reported achievable duty.
When to use it
Use PWM when a modulating demand has to drive an on/off device — an electric heater through an SSR or contactor, a solenoid dosing pump, a trim heater, a resistive load bank — so a 0–100 % controller output becomes a mark-space ratio over a fixed period.
Interface
The published port signature. This is the whole of what the block exposes to your program — the implementation body is not shown here and ships with the download.
Inputs
| Port | Type | Unit |
|---|---|---|
| DUTY | REAL | % |
| PERIOD | TIME | — |
| MIN_ON | TIME | — |
| MIN_OFF | TIME | — |
| ENABLE | BOOL | — |
| SYNC | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| Q | BOOL | — |
| DUTY_ACT | REAL | % |
| PHASE_PCT | REAL | % |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Validation evidence
- Tests
- 11
- Simulated scans
- 582
- Simulator
- v0.1.0
Complete IEC 61131-3 implementation with a published test suite that runs on the vplant simulator. The counts above are that suite, executed on this build.
- Conforms to IEC 61131-3
- Conforms to IEC 61499
Download PWM — free
Create a free Ri Tech account to download the block. You get the Structured Text body, the Rockwell Add-On Instruction (.L5X), the Schneider Control Expert DFB (.XDB), PLCopen XML, the IEC 61499 function block type (.fbt) and the datasheet.
Every block in the catalogue is free to download, in every format, with no purchase and no card. Browsing needs no account at all; downloading needs a signed-in one, so the block lands in your library and re-downloads whenever you need it.
Source is never published on this page. The implementation is released to a signed-in Ri Tech account — free of charge, but never anonymously.